Air Duct Cleaning in St. Louis, MO

EPA does not recommend routine duct cleaning. Its guidance says ducts should be cleaned as needed, not as yearly maintenance, and that cleaning has never been shown to prevent health problems. That is our starting point too: most St. Louis homes do not need it, and we would rather say so than sell it.

Is air duct cleaning worth it?

For most homes, no. EPA says that when no one in the house has allergies or unexplained symptoms, and there is no visible mold or musty smell, cleaning is probably unnecessary. A film of dust on a return register is not proof of a dirty duct system.

Two further points from EPA matter. Studies have not conclusively shown that cleaning ducts lowers the particles in your air. And an inadequate vacuum system can release more contaminants into the house than it removes. A cleaning done badly can leave you worse off.

When does duct cleaning make sense?

Cleaning is reasonable in three situations, all listed by EPA:

• Substantial visible mold on hard duct surfaces or other cooling and heating components. Wet or moldy insulation inside a duct cannot be cleaned effectively and should be replaced, and the moisture source has to be fixed or the mold returns.
• Vermin in the ducts. Rodents or insects that have nested or left droppings.
• Ducts clogged with dust and debris, or particles blowing out of supply registers. A gut renovation that sent drywall dust through an open system is a common example.

In older St. Louis homes, the third case often traces back to a leak. Return ducts that pull from a dusty basement, crawl space or wall cavity will refill the system after any cleaning. Fix the leak, and the cleaning lasts. See duct repair and replacement.

What should a proper duct cleaning include?

A proper job follows a checklist, and EPA publishes the yardstick. Expect these deliverables in the written scope:

1. A visual inspection of ducts, plenums, coil, drain pan and blower before work starts.
2. Access openings cut so the whole system can be reached, including the main trunk.
3. A vacuum that exhausts outside the home or is HEPA-filtered.
4. Contact vacuuming paired with soft-bristled brushing, gentle on fiberglass-lined or flexible duct.
5. Cleaning of the coil, drain pan, blower and heat exchanger, not just the ducts.
6. Access holes sealed and re-insulated.
7. A post-cleaning inspection, with registers and the system running in heat and cool.

Ask for each in writing. If a provider skips the coil and blower, EPA notes those are where cleaning is more likely to improve efficiency.

What should you try before paying for duct cleaning?

Start with cheaper fixes that address dust at its source.

• Filter. EPA recommends MERV 13 or the highest rating your system's fan and filter slot can handle, changed about every 60 to 90 days. See air purifiers and filtration.
• Leaks. ENERGY STAR says about 20 to 30 percent of the air moving through ducts is lost to leaks, holes and poor connections, and leaky ducts can draw attic and basement dust into the house.
• Moisture. Fix any water source before a technician touches a duct.
• Coil and blower service. Your yearly furnace maintenance already looks at the blower.
• Dust at home. Vacuum with a HEPA-rated machine, wash bedding, and cover registers during renovations.

Dryer vent cleaning appears in many duct searches. It is a different exhaust run from your HVAC ducts. Ask whoever you call whether they handle it and whether it is priced separately.

What does air duct cleaning cost in St. Louis?

EPA's duct cleaning guide lists typical costs of $450 to $1,000 per heating and cooling system. The page is undated, so treat it as a rough floor and get current local quotes. We do not quote a price here, because it depends on the work found.

Price drivers are system size, number of returns and supplies, access, the contamination level, and whether coil and blower cleaning is included. Angi reports St. Louis HVAC labor at $75 to $150 per hour (2026), a market figure. If a company bills hourly, EPA suggests asking for an estimate of hours, and getting scope and total cost in writing before work starts. Walk away from anyone selling a whole-house special without looking inside.

Who regulates duct cleaning in St. Louis County and the City?

Nobody vets a duct cleaner for you. EPA sets no duct-cleaning standards, and licensing in Missouri is local.

St. Louis County's Department of Transportation and Public Works says a mechanical permit is needed to install, alter, repair or replace a duct system. A leak repair or a replaced trunk found mid-cleaning is therefore permit work, and the county's Mechanical Licensing Clerk at (314) 615-7096 can confirm a contractor's county license. Inside the City of St. Louis, the Mechanical Section at 314-622-3313 answers permit questions. We found no source that treats cleaning alone as permit work, so confirm with your local building office, and have any repair quote say who pulls the permit.

Why ask a specialist before you book a cleaning

Kenan Corporation was founded in 2010 by Kenan Bruce Martz, who had 20-plus years at St. Louis area HVAC companies and disliked the hard-sell pitches in the trade.

• We look before we sell. The inspection decides whether cleaning, a leak repair, or nothing is the right call.
• We explain what we see. Candice F. wrote on Google that Kenan is great at explaining things and giving options.
• Wrong diagnoses cost money. Wendy R. said another company pushed a new furnace without checking parts. The cause was a capacitor.
• Open 24 hours, with a 4.6★ rating from 29 Google reviews as of October 2026.

Missouri has no statewide HVAC license. Ask any provider for the license number your city or county requires. EPA says it neither sets duct-cleaning standards nor certifies or endorses cleaning companies. We work from Spanish Lake and reach Hazelwood and Bridgeton in about 25 and 30 minutes in normal traffic.

Where ducts get checked before anyone cleans them

The dust source differs from street to street, so the house comes first.

• Spanish Lake: about 5 minutes away; in mid-century ranches with basement furnaces, we first check whether a return pulls basement air.
• Ferguson: cooling ducts in Old Ferguson West houses went in later through closets, attics and chases, so leaks there come before cleaning.
• Florissant: 1960s tract houses often have undersized returns, so airflow and filter checks come first.
• Hazelwood: about four in ten households rent, and an owner weighing a cleaning should apply EPA's three tests.
• Bridgeton: low ground near the Missouri River means damp basements, so insulation and moisture get checked first.
• Jennings: one central return can serve a small 1950s house, and a dirty filter starves it long before the ducts do.
• University City: radiator homes in the older south end have few ducts to clean, while the postwar north has basement runs.
• Maplewood: ducts share chases with plumbing in 1900s houses, so ask how a provider will reach the trunk.
• Kirkwood: finished plaster makes access openings the real question, so settle in writing where holes are cut and sealed.